Von Willebrand Factor in Pregnancy (VIP) Study

For pregnant women with von Willebrand disease (VWD) who by the third trimester do not have von Willebrand factor (VWF) or factor VIII (FVIII) levels > 50-100%, specific guidance is lacking for delivery planning for how high a VWF level should be achieved. Specifically, guidance is lacking on whether VWF replacement therapy should target a VWF minimum level in the 100-150% range, i.e., a range closer to the 200-250% levels observed in normal pregnancy.

This is a prospective, open-label, cohort study using Wilate VWF replacement therapy, trough or minimum VWF levels of 100-150% will be maintained for delivery in women with VWD whose third trimester VWF levels are <100%. This group is termed "non-correctors". Women with VWD whose third trimester VWF levels spontaneously rise to >100% will be assigned to the "corrector" group, and these women will not receive VWF replacement therapy. All patients will receive tranexamic acid for 14 days postpartum. Outcome parameters will be assessed for all patients.

The investigators or qualified research personnel will approach all consecutive pregnant VWD patients until 65 non-corrector patients have completed the study protocol, and up to 30 corrector patients have completed the study protocol. Patients with gestational week 34-38 von Willebrand factor activity (VWF:Act) or von Willebrand factor ristocetin cofactor (VWF:RCo), and/or Factor VIII procoagulant activity (FVIII:C) less than 100 percent will be used to assign patients to the non-corrector group. When VWF collagen binding (VWF:CB) laboratory monitoring can be performed, patients with an isolated VWF:CB type 2 defect can also be enrolled.

Rate of primary postpartum hemorrhage, severe postpartum hemorrhage, secondary postpartum hemorrhage will be measured. Safety and secondary laboratory measures will be assessed.